Short answer: “itchi” is not a standard English word. It is usually a misspelling or misheard form of several different Japanese words or of the English word itchy. Below are the common possibilities and how to tell them apart.

1) Japanese ichi

• Meaning: the number one
• Correct romaji: ichi
• Kanji: 一
• Kana: いち
• Example: 「一月」ichigatsu means January

2) Japanese icchi

• Meaning: agreement, match, conformity
• Correct romaji: icchi
• Kanji: 一致
• Verb form: icchi suru 一致する meaning to agree or to match
• Example: 「意見が一致する」iken ga icchi suru meaning the opinions match

3) Japanese ecchi (often written etchi)

• Meaning: playful or mildly sexual content in slang, common in anime and manga talk
• Correct romaji: ecchi or etchi
• Katakana: エッチ
• Usage: as a noun ecchi, or as an adjective ecchi na meaning lewd or naughty in a light sense

4) English itchy

• Meaning: an uncomfortable skin sensation that makes you want to scratch
• Example: itchy sweater, itchy rash

How to Decide Which One Fits

• Talking about numbers or dates in Japanese: likely ichi
• Talking about two things matching or aligning in Japanese: likely icchi
• Talking about anime, manga, ratings, or fan service: likely ecchi
• Talking about skin or a physical sensation in English: likely itchy

If you share the exact sentence where you saw “itchi,” I can pinpoint the correct meaning and provide the proper spelling and kanji or kana if it is Japanese.